Georg Popp is credited as the first forensic scientist to utilize geological evidence to solve a crime. In October 1904, while working as a forensic scientist in Frankfurt, Germany, Georg Popp was asked to assist in solving the murder of a young woman named Eva Disch, who had been strangled in a field. The murder weapon was Ms. Disch's scarf, and the perpetrator had apparently left his own well-used handkerchief near the body. Upon microscopic examination of the contents of the handkerchief, Georg Popp noted that the enclosed mucous contained particles of snuff and bits of coal. The most forensically interesting aspect of the mucosal contents were a variety of minerals , particularly that of hornblende.
The principal suspect in the case was a man named Karl Laubach, who was known to use snuff, who worked part-time in a gasworks fired by burning coal, and who was also employed part-time at a local gravel pit. Popp examined the body of the murder victim and extracted bits of coal and grains of several minerals, including hornblende, from under her fingernails. Georg Popp was able to obtain the clothing worn by the suspect on the day of the murder; he made a close examination of the legs of Mr. Laubach's trousers and removed a variety of soil samples from them. When he performed a microscopic examination of the soil samples, he discovered a lower layer consistent in makeup to a soil sample previously obtained from the murder scene. When he examined an upper layer of soil from the trousers, he found a mineral blend consistent with soil samples removed from the path between the murder site and the suspect's home.
Popp's forensic scientific conclusion was that the suspect's clothing picked up the lower layer of soil at the scene of the murder; this layer was then covered by mineral-laden mud splashed upon the trousers during the suspect's return home. When interrogated and presented with the analysis of evidence found in his handkerchief and clothing, Karl Laubach confessed to the murder. The publicity surrounding the solution of this case established Georg Popp as a forensic geological expert.
The use of geologic information in forensic settings was established internationally in 1908, when Georg Popp was again called upon to assist in the solution of a murder. In this case, he focused his examination on the shoes of the principal suspect; he examined the layers of dirt encrusted between the sole and the front of the heel. The shoes were known to have been cleaned by the suspect's wife on the night before the murder occurred, so it was Popp's hypothesis that the soil had been sequentially accumulated on the day of the murder with the layer closest to the shoe leather deposited first, and so on. By carefully removing each individual layer of soil and examining it microscopically, Popp was able to retrace the steps, literally, taken by the suspect on the day of the murder. He was able to match the soil from the shoes to the soil surrounding the suspect's home, to the scene of the crime, and to the location where the shoes had been hidden by the suspect. His solution of this case firmly established Georg Popp at the forefront of forensic geology . Georg Popp's microscopic examination of minerals and soil samples set a precedent for the continuing use of soil samples as an integral part of forensic investigation.
see also Crime scene investigation; Geology; Inorganic compounds; Microscopes; Minerals.